Coding...: 2014

2014年9月23日星期二

[SQL] 練習transaction

webform :

transaction
1.在執行中間有出錯,所有的刪除都會返回原始狀態

string str1 = @"DELETE LineItem where OrderId = @OrderId;"; // SQL command 1
string str2 = @"DELETE OrderStatus where OrderId = @OrderId;"; // SQL command 2
string str3 = @"DELETE Orders where OrderId = @OrderId;"; // SQL command 2
SqlConnection conn = NEW SqlConnection(SqlHelper.ConnectionStringOrderDistributedTransaction);
SqlCommand delCommand = NEW SqlCommand(str1, conn);
SqlParameter param = NEW SqlParameter("@OrderId", 2);
delCommand.Parameters.ADD(param);
conn.OPEN();
SqlTransaction trans = conn.BeginTransaction();
delCommand.TRANSACTION = trans;
try
{
delCommand.ExecuteNonQuery();
delCommand.CommandText = str2;
delCommand.CommandType = CommandType.Text;
delCommand.ExecuteNonQuery();
delCommand.CommandText = str3;
delCommand.CommandType = CommandType.Text;
delCommand.ExecuteNonQuery();
trans.Commit();
} // try
catch (Exception excep)
{
trans.ROLLBACK(); // 出現例外就ROLLBACK
logger.Debug(excep.Message);
} // catch
finally
{
conn.Close();
delCommand.Dispose();
conn.Dispose();
trans.Dispose();
} // finally

2014年9月13日星期六

[C#] 執行緒練習

一看就懂

class Program
{
static bool _done;
private static readonly object _locker = new object();
static void Main(string[] args)
{
/*
//a.執行序,並指定委派
Thread t = new Thread(WriteY);
t.Start();
//a.同時,do something on the main thread.
for (int i = 0; i < 1000; i++)
{
Console.Write('x');
}
//b.當前執行序名稱
Console.Write(Thread.CurrentThread.Name);
*/
/*
//c.join 等待此執行序結束
Thread t = new Thread(Go);
t.Start();
t.Join();
//c.休眠 Thread.Sleep(0) Thread.Yield()
Thread.Sleep(TimeSpan.FromSeconds(5)); //封鎖此執行緒五秒
Console.WriteLine("Thread t has ended");
*/
/*
//d.Shared State
//因為兩個執行緒都在同一個實體呼叫GOGO,所以共享_done field,結果就只會顯示一次
Program tt = new Program(); //create a common instance
new Thread(tt.GoGo).Start();
tt.GoGo();
//d.Lambda 表示式也會產生 Shared State
bool done = false;
ThreadStart action = () =>
{
if (!done)
{
{
done = true;
Console.Write("Done");
}
}
};
new Thread(action).Start();
action();
*/
/*
//e.為了避免shared state影響程式
// 使用lock保護值性序安全性(thread-safe)
new Thread(LockGo).Start();
LockGo();
*/
//f. 變數i都指向同一個same memory location
for (int i = 0; i < 10; i++)
{
new Thread(() => Console.Write(i)).Start();
}
for (int i = 0; i < 10; i++)
{
int temp = i;
new Thread(() => Console.Write(temp)).Start();
}
}
static void LockGo()
{
//鎖定
lock (_locker)
{
if (!_done)
{ //所以不用擔心執行緒會同時進來,產生兩個Done問題
Console.Write("Done");
_done = true;
}
}
}
private void GoGo()
{
//第二個執行緒因為_done變成true所以沒反應
if (!_done)
{
_done = true;
Console.WriteLine("Done");
}
else
{
Console.WriteLine("//第二個執行緒因為_done變成true所以沒反應");
}
}
private static void Go(object obj)
{
for (int i = 0; i < 100; i++)
{
Console.Write('x');
}
}
private static void WriteY(object obj)
{
for (int i = 0; i < 1000; i++)
{
Console.Write("y");
}
}
}

2014年8月27日星期三

[WCF] WebClient post api

用於測試WCF資料,作為客戶端傳送資料到wcf

string data = @"
{
""B"" : ""88888888-4444-4444-4444-121212121212"",
""QID"" : ""0610a3ac-4262-4b1b-aa23-3a16edb5c7b3"",
""QID"" : ""1ae67bee-e819-451d-bc20-54dffdf839b8"",
""Anr"" : """",
""Der"" : ""54026fee464f7456"",
""An"" :""1c440ab1-7b00-4dcc-8faa-e1c3f1375eb9""
}";
WebClient webClient = new WebClient();
webClient.Headers["Content-type"] = "application/json";
webClient.Encoding = Encoding.UTF8;
webClient.UploadString("http://localhost:3415/WcfService.svc/TEST", "POST", data);

2014年8月26日星期二

[sql] order by 按照自己希望排序

order by
    case
        when c.Name = '單選' then 0
        when c.Name = '複選' then 1
        when c.Name = '問答' then 2
    end

2014年8月20日星期三

[JS] 定時重新整理 + 停止 + 繼續

當有遇到要將js的 setInternal() 停止再繼續時,請參考下列方式 :

<script type="text/javascript">
var refresh;
//定時重新整理的method
function refreshInterval(){
refresh = setInterval("ReloadPartialView()", 20000);
}
//執行
refreshInterval();
//...
//當觸發特定條件,停止重整
clearInternal(refresh);
//...
//啟動重整
refreshInterval();
</script>

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2014年9月23日 星期二